Sidney ery



. S. FRY.

ELECTROLYTIC PRODUCTION OF OXIDS IN NEUTRAL WATER SOLUTIONS.

APPLlCATlON FILED NOV-13,1916.

1,361,041. Patented Dec. 7, 1920.

/ I W I I V c? MIT/v55 5 .ZMJENTUR H I MAM; 361

A77 Y'S.

UNITED STATES PATENT OFFICE.

SIDNEY FRY, 0F SPREYDON, CHRISTCHURCH, NEW ZEALAND.

Specification of Letters Patent.

Patented Dec. '7, 1920.

I Application filed November 13, 1916. Serial No. 131,161.

To all whom it may concern:

.Be it known that I, SIDNEY FRY, a citizen of New Zealand, residing at 105 Somerfield street, Spreydon, Christchurch, New Zealand, have invented certain new and useful Improvements in the Electrolytic Production of Uxids in Neutral Water Solutions, of which the following is a specification.

Oxide of certain of the metals, iron for instance, are useful as paints and my i11- vention aims chiefly at the economic production of oxids direct from metallic iron, and not from intermediate compounds of iron.

In my practical operation of the invention I use ordinary wooden vats or barrels which are lined with sheet-iron or tinplate which acts as the cathodes.

For the anodes I use sheets (preferably) of scrap-iron, waste tinplate, or other suitable material bolted to wooden supporting frames.

1* or the electrolyte I use a water-solution of a neutral salt of sodium, potassium, ammonium, or calcium, preferably common salt (chlorid of sodium) of a strength such that it will not transfer the metal from the anode to the cathode, or redeposit it as metal, but merely conducts the electric current through the. cell and precipitates or deposits the metal as an hydrated oxid. Too strong a solution is not desirable as there appears to be a wasteful dissociation of the sodium chlorid, some of the chlorin escaping in the gaseous form and some forming a chlorin compound or compounds with a portion of the iron, at the same time forming some alkali in the solution which is undesirable though a small degree of alkalinity does not seem to be detrimental, the important point being to have the solution of such weakness as to insure the deposit of the metal as a hydrated oXid.

On the other hand I find that a very dilute solution is not economical as the ohmic resistance absorbs so much more energy.

1 am enabled to get the best results by keeping the electrolyte as nearly neutral as possible, and this condition I am able to obtain by using the solution of moderate strength as aforesaid and by using a current density of about sixteen to twenty amperes per square foot of anode surface, a high density of current being wasteful.

In the practical working of this process the hydroxid settles to the bottom of the vats, whence I pump it into filtering tanks, from which the clear electrolyte is returned to the vats as required and the hydroxid is filtered, dried and roasted.

In the drawings herewith Figure 2 represents a plan of the vat and fittings in which (a) is the vat, (b) the metal lining forming the cathode, (o) the wooden supporting frame for the anodes and (d) the anodes.

Fig. l is a vertical section with its parts similarly lettered to Fig. 2.

I do not propose confining myself to the exact details of plant and manipulation as set out herein, as the spirit of my invention may be adhered to while making use of many useful modifications of plant and the working thereof.

Having described the nature and objects of my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The method of producing hydro-oXids direct from metals which consists in constituting the metal as the anode in a water solution of a salt of sodium, potassium, ammonium or calcium of a strength which will cause the metal to be deposited as a hydrated mid, and then passing an electric current through the electrolyte.

2. The process of electrolytically produc ing ferric hydroxid direct from iron which consists in constituting the iron as the anode in a water solution of a strength which will cause the metal to be deposited as ferric hydroxid, and passing an electric current through the electrolyte.

In testimony whereof I have signed my name to this specification in the presence of two witnesses.

SIDNEY FRY.

Witnesses 

